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The purpose of this study was to determine the kinematic patterns that maximized the vertical force produced during the water polo eggbeater kick. Twelve water polo players were tested executing the eggbeater kick with the trunk aligned vertically and with the upper limbs above water while trying to maintain as high a position as possible out of the water for nine eggbeater kick cycles. Lower limb joint angular kinematics, pitch angles and speed of the feet were calculated. The vertical force produced during the eggbeater kick cycle was calculated using inverse dynamics for the independent lower body segments and combined upper body segments, and a participant-specific second-degree regression equation for the weight and buoyancy contributions. Vertical force normalized to body weight was associated with hip flexion (average, r = 0.691; maximum, r = 0.791; range of motion, r = 0.710), hip abduction (maximum, r = 0.654), knee flexion (average, r = 0.716; minimum, r = 0.653) and knee flexion-extension angular velocity (r = 0.758). Effective orientation of the hips resulted in fast horizontal motion of the feet with positive pitch angles. Vertical motion of the feet was negatively associated with vertical force. A multiple regression model comprising the non-collinear variables of maximum hip abduction, hip flexion range of motion and knee flexion angular velocity accounted for 81% of the variance in normalized vertical force. For high performance in the water polo, eggbeater kick players should execute fast horizontal motion with the feet by having large abduction and flexion of the hips, and fast extension and flexion of the knees. 相似文献
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Bruno Mezêncio João Pedro Pinho Rudolf Huebner João Paulo Vilas-Boas Alberto Carlos Amadio Julio Cerca Serrão 《Journal of sports sciences》2020,38(8):910-917
ABSTRACTThe aim of this study was to propose a group of parameters able to quantify not only arm coordination but also inter limb coordination. These include the well know index of coordination with the relative duration of the stroke phases and two new parameters: the Index of synchronization (Ids) between arms and legs actions; and the Index of inter limb coordination (IdIC) calculated as the relative foot position during successive arm stroke phases. These parameters were compared between experts and amateur swimmers in a maximal front crawl sprint. The influence of arm stroke in leg kick parameters was also assessed, comparing the full stroke condition with a condition without arms actions. Sixty-five per cent of expert swimmers used synchronized limb actions while 95% of amateur swimmers used non-synchronized limb motions. These synchronized expert swimmers also converged towards a specific coordination pattern between foot position and arm stroke phases. In the condition without arms, both groups changed kick rate and amplitude. The present study reveals the interdependency of arms and legs actions and the importance of coordination and synchronization between limbs. Therefore, the proposed group of overall indexes of coordination provides a more complete marker for the analysis of swimming technique. 相似文献
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垂直冲动动作是花样游泳运动中具有一定代表性的专项持有技术动作，它是完成高难度动作前所必须掌握的一种最基本的技术动作。该以花样游泳垂直冲起动作的教学训练方法为研究内容，根据作执教实践中的一些经验体会，就教学训练过程中，如何让运动员尽快掌握并提高动作质量，在教学和训练方面做了研究，重点探讨了关于模仿教学训练和辅助力量训练的几种有效方法手段。 相似文献
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Vassilios Gourgoulis Alexia Boli Nikolaos Aggeloussis Argyris Toubekis Panagiotis Antoniou Panagiotis Kasimatis 《Journal of sports sciences》2013,31(3):278-289
AbstractThe aim of this study was to examine the influence of leg kick on the pattern, the orientation and the propulsive forces produced by the hand, the efficiency of the arm stroke, the trunk inclination, the inter-arm coordination and the intra-cyclic horizontal velocity variation of the hip in sprint front crawl swimming. Nine female swimmers swam two maximal trials of 25 m front crawl, with and without leg kick. Four camcorders were used to record the underwater movements. Using the legs, the mean swimming velocity increased significantly. On the contrary, the velocity and the orientation of the hand, the magnitude and the direction of the propulsive forces, as well as the Froude efficiency of the arm stroke were not modified. The hip intra-cyclic horizontal velocity variation was also not changed, while the index of coordination decreased significantly. A significant decrease (13%) was also observed in the inclination of the trunk. Thus, the positive effect of leg kick on the swimming speed, besides the obvious direct generation of propulsive forces from the legs, could probably be attributed to the reduction of the body’s inclination, while the generation of the propulsive forces and the efficiency of the arm stroke seem not to be significantly affected. 相似文献
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Veronique Colman Ulrik Persyn Daniel Daly Valere Stijnen 《Journal of sports sciences》2013,31(7):653-665
The aim of this study was to establish differences in intra-cyclic horizontal velocity variation of the body's centre of mass in breaststroke swimmers with flat and undulating styles. Vertical eel-like body waving and trunk rotations were measured to distinguish styles. To reconstruct trunk extension and kyphosis in the poorly visible zone close to the water surface, a semi-automated video-analysis system was developed. From 45 internationallevel swimmers examined, two groups of women and two groups of men were identified, those using the most undulating and those using the flattest styles. Among the men with the flattest style, the maximum and minimum horizontal velocity of the body's centre of mass differed by 76% from the mean swimming velocity; among the women with the most undulating style, the figure was 53%. In the most undulating style, less horizontal velocity variation of the body's centre of mass could be explained by movements of the body parts above the water surface, creating a transfer of momentum: a quick backward upper trunk rotation generates resistance and a quick forward shoulder girdle and upper arm movement, followed by a quick forward upper trunk and head rotation, generates propulsion. In addition, during an upward leg kick, some swimmers generated propulsion similar to that seen in eels. 相似文献
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The aim of this study was to examine the effect of swimming speed on leg-to-arm coordination in competitive unilateral arm amputee front crawl swimmers. Thirteen well-trained swimmers were videotaped underwater during three 25-m front crawl trials (400 m, 100 m and 50 m pace). The number, duration and timing of leg kicks in relation to arm stroke phases were identified by video analysis. Within the group, a six-beat kick was predominantly used (n = 10) although some swimmers used a four-beat (n = 2) or eight-beat kick (n = 1). Swimming speed had no significant effect on the relative duration of arm stroke and leg kick phases. At all speeds, arm stroke phases were significantly different (P < 0.05) between the affected and unaffected sides. In contrast, the kicking phases of both legs were not different. Consequently, leg-to-arm coordination was asymmetrical. The instant when the leg kicks ended on the affected side corresponded with particular positions of the unaffected arm, but not with the same positions of the affected arm. In conclusion, the ability to dissociate the movements of the arms from the legs demonstrates that, because of their physical impairment, unilateral arm amputee swimmers functionally adapt their motor organisation to swim front crawl. 相似文献
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目的：为游泳运动员在水槽中进行水感表型强化训练提供参考和建议。方法：将上海市14名一级男性游泳运动员随机分为两组,A组为实验组,B组为对照组。A组每周安排3次水槽中的水感训练课,B组采用常规的泳池训练,保证两组的训练量一致,实验周期为20周。运用上海市游泳水槽系统的三线运动分析系统对运动员训练前后的技术动作进行分析与诊断,运用Tritonwear游泳运动表现分析系统对运动员训练前后50m自由泳成绩和游效指数进行分析。结果：A组与B组运动员经过一段时间的训练后,50 m自由泳成绩和游效指数都较实验前有了一定的提高;而且A组的50 m自由泳成绩和游效指数相比较B组都得到了明显的提高,实验后A组和B组队员的50 m自由泳成绩和游效指数存在显著性差异。结论：通过水槽中水感表型的多种训练方法,运动员的技术动作得到了改进,划水效果得到了提高,运动成绩也得到了提高。对水感的定量研究是我们未来的研究方向,后期还需要更加深入的研究。 相似文献
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Kicking is a key component of freestyle swimming yet the optimum combination of kick rate and kick amplitude remains unknown. For Paralympic swimmers, with upper and lower limb disabilities, the influence of the kick plays an important role in net force production. To determine optimum kick characteristics, 12 Paralympic swimmers aged 19.8 ± 2.9 years (mean ± s) were towed at their individual peak freestyle speed. The experimental conditions were (i) a prone streamline glide for passive trials and (ii) maximal freestyle kicking in a prone streamline for active trials at different speeds and kick amplitudes. Kick rate was quantified using inertial sensor technology. Towing speed was assessed using a novel and validated dynamometer, and net force was assessed using a Kistler force-platform system. When peak speed was increased by 5%, the active force increased 24.2 ± 5.3% (90% confidence limits), while kick rate remained at approximately 150 kicks per minute. Larger amplitude kicking increased the net active force by 25.1 ± 10.6%, although kick rate decreased substantially by 13.6 ± 5.1%. Based on the current kick rate and amplitude profile adopted by Paralympic swimmers, these characteristics are appropriate for optimizing net force. 相似文献
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Abstract In freestyle swimming the arm action is routinely quantified by stroke count and rate, yet no method is currently available for quantifying kick. In this study, we assessed the validity and reliability of inertial sensor technology (gyroscope) to assess kick count and rate. Twelve Paralympic swimmers completed a 100-m freestyle-swimming time-trial and freestyle kicking-only time-trial three times each in a season. An algorithm was developed to detect the up and down beat of individual kicks from the gyroscope trace. For comparative purposes, underwater video analysis provided the criterion measure. The standard error of the estimate (validity) for kick count, expressed as a coefficient of variation, was 5.9% (90% confidence interval 5.5 to 6.4) for swimming, and 0.6% (0.5 to 0.6) for kicking-only trials. The mean bias for kick count was ?1.7% (?2.4 to ?1.1) for swimming, and ?0.1% (?0.2 to ?0.1) for kicking-only trials. Correlations between the sensor and video for kick count were 0.96 (0.95 to 0.97) for swimming, and 1.00 (1.00 to 1.00) for kicking-only trials. The typical error of the measurement (reliability) between trials was approximately 4% for kick count and rate. The inertial sensors and associated software used generated sufficient validity and reliability estimates to quantify moderate to large changes in kick count and rate in freestyle swimming. 相似文献
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花样游泳运动员的月经与参加比赛和训练安排的相互关系问题，一直是现代花样游泳项目进行科学训练和运动竞赛中人们所关切的重要课题。通过对我国部分花样游泳运动员经期训练和比赛情况的分析研究，探讨花样游泳运动员的月经规律，从而使游泳运动员在经期参加比赛时掌握主动权。 相似文献
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在游泳教学中,如何用量化的指标来科学地评判游泳者的游泳能力一直是游泳学界研究的热点。本文通过检测游泳能力掌握程度的不同对人体水中俯卧滑行能力的影响,讨论不同游泳能力者俯卧滑行能力的差异,反映游泳熟练程度对被动阻力的影响,来检验俯卧滑行能否作为评判游泳能力的强烈因子。选取华南师范大学体育专业38名身体健康的大学生按游泳能力的不同分为三组(平均年龄19岁,身高1.72cm,体重64.23kg)作为实验对象分别测量俯卧滑行的距离。要求实验对象采用双手置于头前蹬边滑行的方式进行测试,以手到池边的距离为测量距离。采用单因素方差分析检验俯卧滑行距离是否存在组间差异。结果表明,游泳能力会影响俯卧滑行距离(被动阻力)。不同水平游泳者其俯卧滑行的距离在统计学中有显著性差异,说明俯卧滑行能力可以作为评判游泳能力的强烈因子。 相似文献
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This research was theoretical and experimental, with an objective of a better understanding of the physics of fin swimming.
The theoretical work followed Lighthill’s slender body theory (1960). Video measurements were made on underwater fin swimmers
swimming in an annular pool (58.6 m in circumference). This study considers only SCUBA divers. Five male swimmers swam at
five speeds between 0.4 m/s-0.8 m/s. Skilled divers consumed less oxygen and had lower kick frequencies at each speed. The
skilled divers adhered to the requirements of the theory, but not the unskilled. Specifically, the fin’s trailing edge (TE)
lateral velocity was greater than the relative velocity of the water at the TE (requirement 1); which is the most forgiving.
The second requirement is more stringent, and requires the TE lateral velocity and the relative velocity of the water at the
TE to be of the same sign. Violating the first requirement sometimes causes a change in the instantaneous thrust’s direction.
Violating the second requirement almost always produced instantaneous thrust in the opposite direction than the diver’s desired
swimming direction. This study found that the Lighthill model can be used to describe diver fin swimming, which was optimised
when the diver met the two requirements required for efficient thrust. 相似文献
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Propulsion, one of the most important factors in front crawl swimming performance, is generated from both the upper and lower limbs, yet little is known about the mechanisms of propulsion from the alternating movements of the lower limbs in the flutter kick (FK). The purpose of this systematic review was to review the literature relating to the mechanisms of propulsion from FK in front crawl. There was limited information about the mechanisms of propulsion in FK. Since movements of the lower limbs are similar between FK and the dolphin kick (DK), mechanisms of propulsion from DK were reviewed to better understand propulsion from FK. Recent evidence suggests that propulsion in DK is generated in conjunction with formation and shedding of vortices. Similar vortex structures have been observed in FK. Visualisation and simulation techniques, such as particle image velocimetry (PIV) and computational fluid dynamics (CFD), are non-invasive tools that can effectively model water flow without impacting swimming technique. These technologies allow researchers to estimate the acceleration of water and, consequently, the propulsive reaction forces acting on the swimmer. Future research should use these technologies to investigate propulsion from FK. 相似文献
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Gary Osmond 《Sport in History》2019,39(1):24-44
The Cavill family of swimmers has been recognised as the ‘first family of Australian swimming’ because of their reputation and achievements as competitive swimmers and for their contributions to swimming promotion, stroke development and instruction in the late nineteenth- and early twentieth-centuries. As a family of British migrants based in Sydney, their memory focuses on Anglo-Australian connections. This emphasis overlooks the American dimension of the Cavill legacy – several family members lived, and died, in the USA and made important contributions to swimming in that country, where they were also celebrated as preeminent figures. This article adopts a transnational perspective, particularly borderlands history approaches, to examine this American connection, viewing the, trans-Pacific crossing from Sydney to San Francisco as an under-appreciated sport border zone. The focus is on contributions made to swimming coaching and teaching, with a biographical spotlight on Percy and Sid Cavill, siblings who contributed in these areas over two decades on both sides of the country. By repositioning Australia and the USA in the Cavill swimming narrative, this article contributes to decentring the nation in this realm of sport history. 相似文献
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Bilateral inter-arm coordination in freestyle swimming: effect of skill level and swimming speed 总被引：1，自引：1，他引：0
The aim of this study was to examine the influence of level of skill and swimming speed on inter-limb coordination of freestyle swimming movements. Five elite (2 males, 3 females; age 18.9+/-1.0 years, height 1.71+/-0.04 m, body mass 62.1+/-7.0 kg) and seven novice (age 22.0+/-2.0 years, height 1.77+/-0.04 m, body mass 74.8+/-9.0 kg) swimmers swam a sprint and a self-paced 25 m freestyle trial. The swimming trials were recorded by four digital cameras operating at 50 Hz. The digitized frames underwent a three-dimensional direct linear transformation to yield the three-dimensional endpoint kinematic trajectories. The spatio-temporal relationship between the upper limbs was quantified by means of the peak amplitude and time lag of the cross-correlation function between the right and left arm's endpoint trajectories. A strong anti-phase coupling between the two arms, as confirmed by peak amplitudes greater than 0.8, was noted for both groups and swimming speeds. Significantly higher (P<0.05) peak amplitudes were observed for the sprint compared with self-paced swimming. No significant differences in the strength of inter-limb coupling were noted between the elite and novice swimmers (P>0.05). Time lags were very close to 0 ms and did not differ between groups or swimming speeds. We conclude that in freestyle swimming, the intrinsic anti-phase (180 degrees phase difference) inter-limb relationship is strongly preserved despite the physically powerful environmental influence of the water and this "preferred" pattern is not affected by level of skill. In contrast, increasing movement speed results in stronger inter-limb coupling that is closer to the anti-phase inter-limb relationship. 相似文献
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Opportunities for ball passing in water-polo may be brief and the decision to pass only informed by minimal visual input. Since researchers using point light displays have shown that the walking or running gait of familiars can be identified, water-polo players may have the ability to recognize team-mates from their swimming gait. To test this hypothesis, members of a water-polo team and a competition swim team viewed two randomized sets of video clips, each less than one second long, of swimmers from both teams sprinting freestyle past a fixed camera. The arm stroke clip sequence showed only the upper body, and the kick sequence showed only the lower body. After viewing each video clip, observers rated their level of certainty as to whether the swimmer presented was a team-mate or not. Discrimination was significantly above chance in both groups. Water-polo players were better able to identify team-mates from their kick, whereas swimmers were better able to do so by viewing arm stroke. Our results suggest that, as with walking and running gait, small amounts of visual information about swimmers can be used for recognition, and so raise the possibility that specific training may be able to improve team-mate classification in water-polo, particularly in newly formed teams. 相似文献
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A non-rotational (NR) shot is now a well-known scoring move in soccer. To execute the NR shot, it is necessary to deprive the ball of any rotational forces during the impact phase. To execute the NR shot, it is natural that the force vector acting from the foot would pass through the ball’s center of gravity; however, the coordinated motion of the lower limb joint’s angular displacement and the pelvis is still unclear. The aim of this study is to estimate the coordinated leg and pelvis motion during the NR shot as compared to that during instep kicking. Four right-leg dominant college league players were asked to perform a NR shot and an instep kick a total of 10 times each. Hip, knee, and ankle joint angular displacements in the sagittal plane and pelvis yaw and roll rotational motions during both types of kicks were calculated with 14 IR reflective markers using a 3D real-time motion analysis system with a 250-Hz sampling. The Euclidean distances of the joint space of the NR shot and the instep kick were also calculated to detect similarities in the coordinated motion of the lower limb. The results showed that the lower limb joint motions in the sagittal plane were not different; however, the pelvis roll and yaw motions were apparently different, and these phenomena could simulate a pendulum motion with changes in both the vertical and horizontal displacements. These results suggest that the coordinated motion of the lower limb joint’s angular displacement shows high similarity between the NR shot and the instep kick, and the pelvis roll and yaw synchronized orientation is essential for achieving the NR shot. 相似文献
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九运会花样游泳比赛技术分析 总被引：3，自引：1，他引：2
对九运会花样游泳决赛技术自选和自由自选技术进行了现场观察 ,并将观察结果与八运会比赛情况进行了比较分析。结果表明 ,八运会后 ,我国花样游泳运动有了明显进步 ,主要表现在运动员技术动作质量有较大提高 ,运动员的能力明显增强 ,自选动作变化多、速度快、力度强、幅度大 ,队形变换快而准确 ,图形变换巧妙 ,托举构思新颖独特 ,成功率高。存在着专项力量较薄弱 ,推进及游泳能力不强 ,表现控制力的规定动作质量较差 ,整套动作的技术难度不高及多样性不足、难度编排单一等问题 相似文献